1. Field of the Invention
The present invention relates to an electric junction box which performs multipoint connection incorporating a bus bar, relay, fuse, electronic components, etc., thereby reducing cost and size by reducing the number of components.
2. Description of the Related Art
An electric junction box having heretofore been used in an automobile wire harness usually incorporates a bus bar, relay, fuse, and electronic parts therein. With the recent increased use of electric equipment to be mounted on an automobile, the number of these parts is increasing, which makes the equipment larger in size with an increasing trend of complicated structures thereof.
For example, with the electric junction box as shown in FIG. 4, a lower case 3 and an upper case 4 are incorporated, respectively, within a lower cover 1 and an upper cover 2 inside a box. A bus bar 5 is installed on an upper surface of the lower case 3, and the upper case 4 is arranged on an upper surface of the bus bar 5. The upper case 4 is lock fastened on the upper surface of the lower case 3. In addition, a housing area for a relay and fuse 6, etc. is provided for the upper case 4, and the upper cover 2 is provided in such a manner that the components are covered and fastened to the lower case 3 with the lower cover 1 being fastened to the lower case 3.
As mentioned above, the bus bar 5 is only placed on the upper surface of the lower case 3, and the upper case 4 is arranged therewith. A surrounding wall 4a of the upper case 4 is inserted externally around a surrounding wall 3a of the lower case 3, and a locked area formed with the surrounding walls 4a and 3a is fastened, so that the bus bar 5 is firmly held.
As mentioned above, the conventional electric junction box forms a multipart structure comprising a lower cover, lower case, upper case, upper cover and box. In addition, because the bus bar 5, fuse, relay, electronic components, etc. are mounted thereon, it requires a large number of components, increasing the number of assembly processes and making the cost higher. Furthermore, a larger number of components inevitably increases the weight and also the capacity.